上文講了普通界面的雙向數據綁定,本文講一下recyclerview的雙向數據綁定,整個工程只要寫一個adapter就夠了,不用像以前一個recyclerview寫一個adapter了,節省了至少80%的代碼,什麼第三方庫都不需要了。強大的工具!
1. 創建一個通用的adapter類,採用泛型來傳入對應的model
public class ZLBindingAdapter<T> extends RecyclerView.Adapter<ZLBindingAdapter.BindingHolder> {
private List<T> items ;
private int variableId;
private int layoutId;
public ZLBindingAdapter(List<T> items, int variableId, int layoutId) {
this.items = items;
this.variableId = variableId;
this.layoutId = layoutId;
}
@NonNull
@Override
public BindingHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType) {
ViewDataBinding binding = DataBindingUtil.inflate(LayoutInflater.from(viewGroup.getContext()), layoutId, viewGroup, false);
return new BindingHolder(binding);
}
@Override
public void onBindViewHolder(@NonNull BindingHolder bindingHolder, int i) {
bindingHolder.bindData(items.get(i));
}
@Override
public int getItemCount() {
return items.size();
}
public class BindingHolder<T> extends RecyclerView.ViewHolder {
ViewDataBinding binding;
/**
* @param binding 可以看作是這個hodler代表的佈局的馬甲,getRoot()方法會返回整個holder的最頂層的view
* */
public BindingHolder(ViewDataBinding binding) {
super(binding.getRoot());
this.binding = binding;
}
public void bindData(T item) {
binding.setVariable(variableId ,item);
}
}
}
items就是我們的數據列表,這裏我們是user的數據
variableId就是綁定的model對象,比如我們綁定user這個對象,variableId就是BR.user
layoutId是我們佈局文件的id。
2. 然後我們的activity是這麼寫的。
recyclerView = findViewById(R.id.recyclerview);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
ZLBindingAdapter<User> bindingAdapter = new ZLBindingAdapter(users, BR.user, R.layout.item_belle);
recyclerView.setAdapter(bindingAdapter);
recyclerView.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL));
3. 看效果:
強大吧,列表出來了。
我們要什麼類型,只要對應的泛型傳入即可,所有recyclerview通用一個adapter!!